Haptic motor

ABSTRACT

A method of forming a seat cushion of a vehicle seat includes locating a motor in a first portion of a housing, and positioning a second portion of the housing on the first portion of the housing, wherein one of the first and second portion of the housing includes a meltable feature located near a location of contact of the first and second portion. The meltable feature is melted to permanently secure the first and second portion together and provide a sealed housing that retains and seals the motor. The sealed housing is suspended in a mold with a rod. Liquid foam is poured into the mold, and the liquid foam is allowed to solidify to form a solid foam seat cushion that encapsulates the sealed housing and embeds the sealed housing in the foam cushion. The sealed housing prevents the liquid foam from contacting the motor.

REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 13/475,081 filed on May 18, 2012, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

A driver can be exposed to numerous audio and visual signals and stimuli during driving. If an event occurs while driving, an audio or visual alert can be generated to obtain the driver's attention. In one example, an event occurs when a sensor detects that a vehicle deviates from its lane. However, due to numerous other audio and visual signals and stimuli to which the driver is exposed, an audio or visual alert might not get the attention of the driver.

A tactile alert can be provided to alert the driver of an event. In one example, a motor located in a seat cushion vibrates when an event occurs to provide a tactile alert to the driver. Prior motors include a metal motor housing including portions that are secured together by fasteners. The metal housing is not water-resistant, and liquid foam cannot be used to form the seat cushion with the motor in place as the liquid foam could leak inside the metal housing. Therefore, the cushion is molded to include grooves that receive the motor. The motor is externally visible once the motor is positioned in one of the grooves. An additional pad may be located over the motor in the groove to provide a smooth surface.

SUMMARY OF THE INVENTION

An example method of forming a seat cushion of a vehicle seat includes locating a motor in a first portion of a housing, and positioning a second portion of the housing on the first portion of the housing, wherein one of the first and second portion of the housing includes a meltable feature located near a location of contact of the first and second portion. The meltable feature is melted to permanently secure the first and second portion together and provide a sealed housing that retains and seals the motor. The sealed housing is suspended in a mold with a rod. Liquid foam is poured into the mold, and the liquid foam is allowed to solidify to form a solid foam seat cushion that encapsulates the sealed housing and embeds the sealed housing in the foam cushion. The sealed housing prevents the liquid foam from contacting the motor. The rod is removed.

These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a cushion of a vehicle seat;

FIG. 2 illustrates a flowchart of a method of making the cushion;

FIG. 3 illustrates a perspective view of a motor showing internal components;

FIG. 4 illustrates a side cross-sectional view of the motor;

FIG. 5 illustrates a front cross-sectional view of the motor;

FIG. 6 illustrates a cross-sectional view of a housing of the motor including projections and grooves of each of an upper portion and a lower portion of the housing;

FIG. 7 illustrates a perspective view of the motor including an adhesive on the housing;

FIG. 8 illustrates a perspective view of the cushion with ventilation foam placed over an upper surface of the cushion;

FIG. 9 illustrates a perspective view of foam placed over the motors embedded in the cushion;

FIG. 10 illustrates a cross-sectional view of the cushion taken along lines A-A of FIG. 8;

FIG. 11 illustrate a side view of a driver sitting on the cushion of a vehicle seat including the motor; and

FIG. 12 illustrates a top view of the driver sitting on the cushion of the vehicle seat including the motor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a cushion 20 of a vehicle seat. The cushion 20 is formed by a molding process (described below) and includes a seat portion 22 having a substantially flat upper surface 24 and two side bolsters 26 each located on one side of the seat portion 22. In one example, the cushion 20 is made of foam. In one example, the cushion 20 is made of polyurethane foam.

As discussed below, at least one motor 28 (shown in FIGS. 3, 4 and 5) is embedded within the cushion 20 at a desired location. In one example, the at least one motor 28 is completely embedded within the foam of the cushion 20 such that the at least one motor 28 is not visible when viewing an external surface of the cushion 20. In another example, the at least one motor 28 could be use with a cushion that includes pre-formed grooves in which the at least one motor 28 can be located. In one example, there are two motors 28 that are each embedded in one of the two side bolsters 26.

FIG. 2 illustrates a method 30 of making the cushion 20. In step 32, at least one motor 28 is suspended by a rod (not shown) or similar structure in a desired position within a mold (not shown). A rod with a magnetic tip or a mechanical device can be employed to retain the at least one motor 28 in the desired position. In step 34, liquid foam is poured into the mold. In one example, the liquid foam is polyurethane foam. In step 36, the foam is heated and/or baked, and the foam expands and solidifies to form the solid cushion 20. As a result, the at least one motor 28 is encapsulated and embedded in the foam of the cushion 20. In step 38, the rod is then removed from the at least one motor 28, defining a hole in the foam of the cushion 20 where the rod was previously positioned. In one example, removal of the rod defines an approximately 6 mm diameter hole in the cushion 20 where the rod was previously located.

FIGS. 3, 4 and 5 illustrate a motor 28 that is embedded in the cushion 20. In one example, the at least one motor 28 is a haptic motor. In one example, the at least one motor 28 is a vibration motor. The motor 28 includes a DC motor 40 and an eccentric weight 42, or a counter weight, located within a sealed housing 44. In one example, the housing 44 is made of nylon. There is no contact between the eccentric weight 42 and the housing 44. In one example, there is a minimum clearance of approximately 1.4 mm between the eccentric weight 42 and the housing 44. There is no looseness or rattle allowance between the DC motor 40 and the housing 44, preventing any abnormal noise due caused by DC motor 40 to housing 44 vibration. Additionally, there is no looseness or rattle between the eccentric weight 42 and a motor shaft 52. Finally, as the housing 44 is sealed, the rotating parts of the motor 42 are protected from the environment, preventing erosion and corrosion. A wire harness subassembly 54 extends from the motor 28. The wire harness subassembly 54 is secured to the motor 28 by a grommet 82.

Returning to FIG. 1, the wire harness subassembly 54 allows communication between the motor 28 and a controller 79. The controller 79 is also in communication with a sensor 80 that detects a road event, as explained below.

The housing 44 includes an upper portion 46 and a lower portion 48 secured together by welding. In one example, the upper portion 46 and the lower portion 48 are secured together by sonic welding. Once welded, the housing 44 is leak proof and sealed, which prevents the liquid foam from entering the housing 44 and affecting the operation of the at least one motor 28. The housing 44 also eliminates minimum free play or vibration loss in the housing 44. In one example, the upper portion 46 and the lower portion 48 are each substantially u-shaped.

As shown in FIG. 5, the housing 44 includes a top surface 72, a bottom surface 74, a first longitudinal surface 76 and a second longitudinal surface 78. In one example, the top surface 72 is substantially flat. In one example, the bottom surface 74 includes a portion that is substantially rounded.

The shape of the housing 44 can be designed for maximum comfort. The surface area of the top surface 72 of the housing 46 is maximized (that is, it is substantially flat) to distribute the contact load over the broadest possible area without extending beyond the natural intrinsic width and length of the motor 28. In one example, the top surface 72 of the housing 44 is substantially parallel to a top surface 110 of the bolster 26 of the cushion 20 (shown in FIG. 10). A strong bond forms between the upper portion 46 and the lower portion 48 of the housing 44 such that the housing 44 can accept pressure, such as the pressure applied by a knee of person when kneeling on the vehicle seat.

As shown in FIG. 6, a perimeter of each of the upper portion 46 and the lower portion 48 includes a projection 56 and 58, respectively, that engages a groove 64 and 66, respectively, of the other of the projections 56 and 58, respectively, when the upper portion 46 and the lower portion 48 are placed together. Each groove 64, 66 defines a respective ledge. The projections 56 and 58 extend around an entire perimeter of the upper portion 46 and the lower portion 48, respectively, except at the location where the grommet 82 is received in the housing 44. In one example, the projection 58 of the lower portion 48 is located inwardly with respect to the projection 56 of the upper portion 46.

One of the projections 56 and 58 includes a bead 68 that extends around the perimeter of the respective projection 56 and 58 and is located near a location of contact of the upper portion 46 and the lower portion 48 of the housing 44 when placed together. In one example, the bead 68 is located in the groove 64 of the upper portion 46 of the housing 44. In one example, the bead 68 has a generally triangular shape having a width X and a height Y. In one example, the width X is approximately 0.3 mm, and the height Y is approximately 0.3 mm. When the upper portion 46 and the lower portion 48 are positioned together and are sonic welded, the bead 68 melts and fills in the grooves 64 and 66, securing the upper portion 46 and the lower portion 48 together.

As shown in FIG. 7, in one example, an adhesive 70 can be employed to secure the housing 44 to the foam of the cushion 20 when the at least one motor 28 is used with a cushion that includes pre-formed grooves in which the at least one motor 28 can be received. In one example, the adhesive 70 is double sided peel and stick tape. In one example, the adhesive 70 is applied to one or more of the top surface 72, the bottom surface 74, the first longitudinal surface 76 and the second longitudinal surface 78 of the housing 44. However, it is possible for no adhesive to be employed as the housing 44 of the motor 28 is embedded in the foam of the cushion 20 during the molding process described in FIG. 2.

FIG. 8 illustrates a perspective view of the cushion 20 including two motors 28 (shown in phantom) each embedded in one of the two bolsters 26. A mat 84 is located over the flat upper surface 24 of the seat portion 22 of the cushion 20. The mat 84 includes holes 86 that allow for ventilation. In one example, the mat 84 is made of polyester.

FIG. 9 illustrates a perspective of the cushion 20 including a piece of foam 88 located over each of the two motors 28 on an exterior surface of the cushion 20. In one example, a piece of foam 88, such as a mat, can be located over the two motors 28 to provide additional cushioning to protect the motors 28 and to also prevent the motors 28 from causing driver discomfort. In one example, each piece of foam 88 is made of polyurethane. However, in another example, there is no piece of foam 88 located over each of the two motors 28 as the embedding of the two motors 28 in the cushion 20 provides cushioning.

FIG. 10 illustrates a cross-sectional view of a portion of the cushion 20 taken along line A-A of FIG. 8. As shown, the foam material of the cushion 20 surrounds and is located above the motors 28 such that the motors 28 are embedded within the cushion 20 and are not visible when viewing the cushion 20 from an external perspective. A trim cover 104 is located over the cushion 20 and provides an external surface of the vehicle seat in which the driver sits while driving.

The at least one motor 28 is positioned in the cushion 20 such that it will vibrate to provide a tactile signal that will be felt by the driver when activated by the controller 79. However, the at least one motor 28 is positioned to prevent pinching of and pressure on the driver. As explained below, the at least one motor 28 is positioned such that vibrations generated by the at least one motor 28 will be felt by the 5^(th) percentile female based on size and the 95^(th) percentile male based on size.

FIG. 11 illustrates a side view of a driver 90 sitting in a vehicle seat 92, and FIG. 12 illustrates a top view of the driver 90 sitting in the vehicle seat 92. A torso centerline 94 extends through a center body 96 of the driver 90 when seated in the vehicle seat 92. A thigh centerline 98 is substantially parallel to a thigh 100 of the driver 90 when seated in the vehicle seat 92 and extends through the center body 96. The torso centerline 94 and the thigh center line 98 intersect at a point H, or the H point. A plane (not shown) is defined by the torso centerline 94 and the thigh centerline 98. A circle 102 is defined around the point H having a radius of Z. In one example, Z is approximately 12.5 mm. The center body 96 of the driver 90 rests against a backrest 106 of the vehicle seat 90, and the thigh 100 is positioned on the cushion 20.

As shown in FIGS. 11 and 12, two motors 28 are each embedded in one of the side bolsters 26 of the cushion 20. The eccentric weight 42 of each motor 28 is positioned in the cushion 20 relative to the point H. The eccentric weight 42 of each motor 28 is positioned a distance of approximately A+/−12.5 mm below the thigh centerline 98, approximately B mm+/−12.5 mm from a side of the plane, and approximately C+/−12.5 mm from a side of the thigh centerline 98. In one example, A is approximately 65 mm, B is approximately 0 mm, and C is approximately 185 mm. The motors 28 are also positioned at least approximately 7.5 mm below an upper surface of the cushion 20.

By using these values and ranges to determine the position of each of the two motors 28, the optimal position of each of the motor 28 in the cushion 20 can be determined, and the motors 28 are then positioned in this location within the mold prior to pouring in the liquid foam to form the cushion 20. The at least one motor 28 is therefore positioned such that vibrations generated by the at least one motor 28 will be felt by the 5^(th) percentile female based on size and the 95^(th) percentile male based on size.

Returning to FIG. 1, the sensor 80 monitors a road event. In one example, a road event occurs when the vehicle moves from its lane, another vehicle is approaching, a front collision occurs, or a rear collision occurs. When the sensor 80 detects a road event, a signal is sent to the controller 79. The controller 79 then sends a signal to the at least one motor 28. In response to the signal from the controller 79, the at least one motor 28 vibrates in the cushion 20 to provide a tactile signal that can be felt by the driver to alert the driver of the road event. In one example, the at least one motor 28 vibrates above 50 m/s² as measured at a seat-occupant interface at approximately 74 Hz.

The foregoing description is only exemplary of the principles of the invention. Many modifications and variations are possible in light of the above teachings, for instance, the inlet vanes may also have intermediate positions. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than using the example embodiments which have been specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention. 

What is claimed is:
 1. A method of forming a seat cushion of a vehicle seat, comprising: locating a motor in a first portion of a housing; positioning a second portion of the housing on the first portion of the housing, wherein one of the first and second portion of the housing includes a meltable feature located near a location of contact of the first and second portion; melting the meltable feature to permanently secure the first and second portion together and provide a sealed housing that retains and seals the motor; suspending the sealed housing in a mold with a rod; pouring liquid foam into the mold and allowing the liquid foam to solidify to form a solid foam seat cushion that encapsulates the sealed housing and embeds the sealed housing in the foam cushion, wherein the sealed housing prevents the liquid foam from contacting the motor; and removing the rod.
 2. The method of claim 1, wherein said allowing the liquid foam to solidify comprises heating the liquid foam.
 3. The method of claim 1 wherein the meltable feature comprises a bead extending around a perimeter of one of the first portion and the second portion of the housing.
 4. The method of claim 3, wherein said melting the meltable feature comprises performing sonic welding on the bead to form a sonic weld.
 5. The method of claim 4, wherein the sonic weld melts the bead into a groove of the first or second portion.
 6. The method of claim 3, wherein the bead has a triangular cross-sectional shape.
 7. The method of claim 1, wherein the melted feature is located closer to an inner surface of the sealed housing than to an outer surface of the sealed housing.
 8. The method of claim 1, comprising vibrating the motor within the seat cushion in response to a road event.
 9. The method of claim 1, wherein the seat cushion includes a seat portion having a substantially flat seating surface and a bolster on each side of the seat portion, and said suspending and pouring are performed such that the sealed motor assembly is located in one of the two bolsters.
 10. The method of claim 1, wherein said suspending the sealed housing in a mold comprises orienting the sealed housing such that a substantially flat surface of an upper one of the first and second housing portions is substantially parallel to a top surface of the seat cushion.
 11. The method of claim 10, wherein the substantially flat surface of said upper one of the first and second housing portions extends longitudinally in a direction parallel to a motor shaft of the motor.
 12. The method of claim 1, comprising: a sensor detecting a road event and sending a signal to a controller based on the detected road event; and the controller receiving the signal from the sensor and sending another signal to the motor to cause the motor to vibrate within the seat cushion based on the detected road event.
 13. The method of claim 1, wherein said positioning the second portion of the housing on the first portion of the housing comprises abutting a rim of the first portion against a rim of the second portion along an outer perimeter of the housing.
 14. The method of claim 1, wherein: a rim of one of the housing portions comprises a first ledge at an outer surface of said one of the housing portions, and a first projection at an inner surface of said one of the housing portions that extends beyond the first ledge; the rim of the other of the housing portions comprises a second ledge at an inner surface of said other of the housing portions, and a second projection at an outer surface of said other of the housing portions that extends beyond the second ledge; and said positioning comprises abutting the first projection against the second ledge, abutting the second projection against the first ledge, and abutting the first and second projections against each other.
 15. The method of claim 14, wherein said positioning comprises: arranging the outer surface of said one of the housing portions and the outer surface of said other of the housing portions to be flush with each other; and arranging the inner surface of said one of the housing portions and the inner surface of said other of the housing portions to be flush with each other.
 16. The method of claim 14, wherein said positioning comprises providing the meltable feature between the first projection and the second ledge or between the second projection and the first ledge for said melting.
 17. The method of claim 1, wherein the liquid foam is a polyurethane foam.
 18. The method of claim 1, wherein the first and second housing portions are made of nylon.
 19. The method of claim 1 wherein the first housing portion has a different shape than the second housing portion. 